Imidacloprid 17.8% SL is a systemic soluble-liquid insecticide used against specific sucking pests and a limited number of other labelled pests. Its correct rate depends on the crop, pest, water volume, application equipment, and waiting period.
Do not select a dosage by concentration alone. Among available insecticides, the same active ingredient may be sold as SL, SC, WG, WS, FS, or granules, and each formulation has separate directions.
What Does 17.8% SL Mean?
The formulation contains imidacloprid in a soluble-liquid form at the declared concentration. It is intended to be diluted and applied according to the crop-pest label claim. It is not the same as an imidacloprid seed-treatment formulation.
Indian Label-Claim Rate Examples
| Crop | Target pest | Active ingredient | 17.8% SL formulation | Water | Waiting period |
|---|---|---|---|---|---|
| Cotton | Aphid, whitefly, jassid, thrips | 20–25 g/ha | 100–125 ml/ha | 500–700 L/ha | 40 days |
| Paddy | Brown, white-backed and green leaf hoppers | 20–25 g/ha | 100–125 ml/ha | 500–700 L/ha | 40 days |
| Chilli | Jassid, aphid, thrips | 25–50 g/ha | 125–250 ml/ha | 500–700 L/ha | 40 days |
| Sunflower | Whitefly, jassid, thrips | 20 g/ha | 100 ml/ha | 500 L/ha | 30 days |
| Okra | Aphid, jassid, thrips | 20 g/ha | 100 ml/ha | 500 L/ha | 3 days |
| Groundnut | Aphid, jassid | 20–25 g/ha | 100–125 ml/ha | 500 L/ha | 40 days |
| Tomato | Whitefly | 30–35 g/ha | 150–175 ml/ha | 500 L/ha | 3 days |
The official table also includes crop-specific uses for sugarcane, mango, citrus, and grapes. Tree-crop rates and water volumes depend on tree size and equipment and should be taken directly from the product label.
Why “Millilitres per Litre” Can Be Misleading
A hectare rate is tied to a specified water volume. Converting it to millilitres per litre without considering field area, canopy size, and equipment may cause under- or overdosing.
For example, the same formulation rate spread in 500 litres and 700 litres per hectare produces different tank concentrations but the same field dose. Calculate the required product from the treated area first.
Application Steps
- Confirm the crop, pest, and 17.8% SL formulation on the label.
- Measure the treated area.
- Select the label rate within the approved range.
- Calibrate sprayers to determine water output per hectare.
- Mix the measured product as directed.
- Apply uniformly without runoff.
- Record the waiting period and expected harvest date.
Application on Tomato
The official 17.8% SL claim for tomato targets whitefly at 150–175 ml per hectare in 500 litres of water, with a three-day waiting period. This rate is not an automatic recommendation for thrips, mites, fruit borers, or leaf miners.
Tank Mixing and Adjuvants
Do not add other pesticides, fertilizers, or adjuvants unless compatibility and crop safety are confirmed. A mixture can alter pH, increase penetration, cause phytotoxicity, or expose the pest to unnecessary modes of action.
Resistance Prevention
- Use only when scouting shows the target pest requires treatment.
- Do not repeat Group 4A insecticides against consecutive pest generations.
- Rotate to a different effective mode of action.
- Preserve predators and parasitoids.
- Use full label rates rather than sublethal doses.
Safety and Residue Precautions
Wear the label-specified protective equipment. Avoid inhalation and skin or eye contact. Do not spray into wind or near water bodies. Keep people and animals away during application and observe the re-entry interval.
Waiting periods differ sharply by crop. A three-day interval on one vegetable does not cancel a 40-day interval on another crop.
Role in Crop Protection
Use imidacloprid 17.8% SL within integrated crop protection, including monitoring, sanitation, balanced fertilizer use, suitable planting dates, natural enemies, and resistance rotation.
Final Thoughts
Imidacloprid 17.8% SL rates range considerably across crops. Use the current label in hand, calculate by field area, calibrate spray volume, and never transfer rates between formulations or crops.
